SUMMARY
Every year sees the construction thousands of square metres of building structures and slabs using successive levels of shoring. This system is based on resting the auxiliary shoring structures on recently poured slabs. The savings in time and cost of these construction systems stem mainly from the possibility of recovering most of the components used in the shortest possible time. In Spain, with this objective in mind, a method known as clearing (or partial striking) is used. The technique consists of removing the formwork and 50% of the shores which hold up the slab, a few days after the pouring of concrete.
Clearing is very used in Spain; however, it has been very little studied to date. Therefore, there is now uncertainty about the manner in which loads are transmitted between slabs and shores during the construction of the structure. This PhD thesis studies the transmission of loads between slabs and shores, during the construction of slabs using successive levels of shoring. This study is part of the research project “Estudio experimental y numérico de la construcción de forjados hormigonados in situ mediante sistemas de cimbrado y descimbrado”, funded by Ministerio de Educación y Ciencia de España, project BIA 2004-02085. This research was performed in Instituto de Ciencia y Tecnología del Hormigón (ICITECH), Universidad Politécnica de Valencia.
To determine the influence of clearing on the transmission of loads between slabs and shores, an experimental study was carried out. In this study, we measured the distribution of loads on shores during the construction of a full-scale 3-storey building, with thick slabs made up of reinforced concrete. From the experimental study, it has been demonstrated that after clearing, a significant part of the loads (self weight) are transferred to slabs.
In another phase of the research, a finite element model has been developed, the objective being the simulation of the construction process followed in the building analysed in the experimental study. The finite element model has been calibrated by comparing experimental and numerical results. Once the model has been calibrated, new models have been developed in order to compare different construction processes.
In the last part of the thesis, the degree of adjustment between various simplified methods available in the literature has been checked. Advantages and disadvantages of each method have been presented, with regard to the estimation of the transmission of loads between slabs and shores when the clearing operation is used.
Keywords: Clearing; Shoring; Striking; Shore; Reinforced concrete buildings; Slabs; Experimental study; Finite element method.
Estudio de la construcción de forjados hormigonados in situ empleando el clareado

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